While installing I noticed the url and download_url point to @mistercrunch's repo:

https://github.com/airbnb/airflow/blob/9a791999b871d5f19550cbf882fbd09037d99e52/setup.py#L69

    url='https://github.com/mistercrunch/Airflow',
    download_url=(
        'https://github.com/mistercrunch/Airflow/tarball/' + version),

Is that the correct repository to install and update from?